How Green Is My City

It was to be the ultimate urban paradise. Hundreds of pages of plans, maps and charts detailed the construction of a state-of-the-art eco-city called Dongtan on China’s Chongming Island, at the mouth of the Yangtze River. Energy-efficient buildings would be clustered together to encourage residents to travel on foot; only battery- or hydrogen-powered cars would be permitted in the development. Surrounding organic farms would supply food; sea breezes and the burning of husks of China’s staple crop, rice, would furnish power. Canals and ponds would incorporate the local wetlands, providing restful views for humans and continued respite for migrating birds.

Yet for all its grand goals, this island city-to-be remains unbuilt. Whether China has abandoned the project totally is unclear. It was originally slated for completion in 2010 but has failed to proceed beyond the construction in 2009 of a tunnel and bridge linking Chongming to the mainland. It is one of numerous planned eco-cities around the world that have fizzled, many because of cost. Even if every planned eco-city were successful, however, their effect on overall energy use and emissions would be minimal because the vast majority of urbanites would still live in existing cities. All these reasons suggest that we cannot rely on new construction to fully address the challenges of feeding, housing and transporting urban populations in ecologically sound ways. We need another solution.